20643975002100 has 144 divisors (see below), whose sum is σ = 60514033728960. Its totient is φ = 5433138048000.

The previous prime is 20643975002047. The next prime is 20643975002137. The reversal of 20643975002100 is 120057934602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8395531 + ... + 10572269.

It is an arithmetic number, because the mean of its divisors is an integer number (420236345340).

Almost surely, 2^{20643975002100} is an apocalyptic number.

20643975002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20643975002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30257016864480).

20643975002100 is an abundant number, since it is smaller than the sum of its proper divisors (39870058726860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20643975002100 is a wasteful number, since it uses less digits than its factorization.

20643975002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2177170 (or 2177163 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 39.

The spelling of 20643975002100 in words is "twenty trillion, six hundred forty-three billion, nine hundred seventy-five million, two thousand, one hundred".